278 



ZOOLOGY. 



oe 



Fis. ~'32. Intesiin<> and testis (t) of a copepod 

 (Plevroma), ^irle view , cesophagus ; t>, stomach ; 

 h, blind sac leadiiiir from the stomach ; i, intes- 

 tine; c, hean ; mi, coiied vas deferuns. After Clans, 

 from Gegenbaur. 



In Lerneonema radiata Steenstrup and Lutken (Fig. 234), 

 we find the lowest term in the series of degradational forms 



of this order. The 

 / mouth-parts are here 



converted into five 

 roots, radiating from 

 the head ; the body 

 is not segmented, and 

 ends in two long egg- 

 masses. 



In Penella (Fig. 

 236) the body is cord- 

 like, buried in the 

 flesh of the sun-fish or sword-fish, etc., the females having 

 two long, string-like 

 egg-sacs. The speci- 

 men figured was taken 

 from a sword-fish off 

 Portland, Maine. 



In Lcrncea branchia- 

 lis Linn, of the gills of 

 the cod, the body is 

 thicker, the root-like 

 appendages grow deep 

 into the flesh of its 

 host, like twisted and 

 gnarled roots, while the 

 shapeless sac-like body 

 is filled with eggs. 



In Adheres, we as- 

 cend a step higher in 

 the perfection of or- 

 gans ; the creature is 

 attached by a pair of 



, . i ., Fig. 233. Cantkocamplus caver- Fig. 334. 



jaWS WillCil lllllte tO narum of Mammoth Cave, much Fish -louse of 

 P i j i enlarged. the Menhaden. 



form a sucker, the an- twice enlarged! 



tennae are present, though rudimentary, while AfterVern11 - 

 the abdomen is faintly segmented. A. Carpenter i Packard 

 (Fig. 235) lives on the trout in Colorado. 



